I'd recommend that you view the cluster configuration for all 3 of your servers by going to the url and verify that they are all configured the same.
Here's the snippet from the jboss manual about how to check the configuration.
You can view the current cluster information by pointing your browser to the JMX console of any JBoss instance in the cluster (example,
http://hostname:8080/jmx-console/) and then clicking on the jboss:service=DefaultPartition MBean (change the MBean name to reflect your cluster name if this node does not join DefaultPartition). A list of IP addresses for the current cluster members is shown in the CurrentView field.
Daniel